1.1: magnesium bromide diethyl etherate; butanethiol / diethyl ether / 15 h / 20 °C 1.2: 77 percent / camphorsulfonic acid / CH2Cl2 / 18 h / 20 °C 2.1: 94 percent / cerium trichloride; sodium borohydride / methanol / 0.5 h / 0 °C 3.1: triphenylphosphine; diethyl azodicarboxylate; 4-nitrobenzoic acid / tetrahydrofuran / 12 h / 20 °C 3.2: 86 percent / sodium methoxide / methanol / 1 h / 20 °C 4.1: 92 percent / imidazole / dimethylformamide / 2 h / 40 °C 5.1: t-butyllithium / diethyl ether; pentane / 0.5 h / -78 °C 5.2: 51 percent / TMEDA / diethyl ether; pentane / 0.08 h / -78 °C 6.1: 90 percent / Dess-Martin periodinane; sodium bicarbonate / CH2Cl2 / 1 h / 20 °C 7.1: TBAF / tetrahydrofuran / 0.5 h / 0 °C 8.1: 25 mg / HCl / 2-methyl-butan-2-ol / 2 h / 20 °C 9.1: 83 percent / imidazole / dimethylformamide / 2 h / 20 °C 10.1: 87 percent / DDQ / CH2Cl2; H2O / 0.5 h / 20 °C 11.1: 81 percent / pyridine / CH2Cl2 / 0.17 h / -78 °C 12.1: 9-BBN / tetrahydrofuran / 2 h / 40 °C 12.2: 37 percent / thallium carbonate; triphenylarsine / [1,1'-bis(diphenylphosphino)ferrocene]dichloropalladium(II) / tetrahydrofuran; dimethylformamide; H2O / 12 h / 20 °C 13.1: 78 percent / TBAF / tetrahydrofuran / 0.5 h / 0 °C View Scheme